Question

Explain the types of volcanoes on the basis of periodicity of eruption with examples.

Answer 1

The eruption classification of volcanoes is as follows:

1. Classification according to Eruption: Volcanoes are classified according to eruption into the following two types:
   1. Central-type or conical volcano:
      
      • When a volcano erupts, lava forms a large tube-like path and flows out through these tube-like channels. This is called a central volcano.
      • When lava comes out, it spreads around the mouth of this vent, forming cone-shaped mountains and conical volcanic mountains.
      • Eg., Mt. Fujiyama in Japan and Mt. Kilimanjaro in Tanzania are examples of central-type volcanoes and conical mountains.
   2. Fissure-type volcanoes:
      
      • During the eruption, when the magma comes out not from a single vent but from many cracks (fissures), it is called a fissure-type volcanic eruption.
      • The molten material coming out with the eruption spreads on both sides of the fissure.
      • As a result, volcanic plateaus are formed.
      • Eg., The Deccan Plateau of India has also been formed due to such a type of volcanic eruption.
2. Classification according to the period of eruption: Volcanoes are classified into three types according to the period of eruption:
   
   1. Active Volcano: If the volcanic eruptions are regular even in the present times, then such volcanoes are called active volcanoes. ex. Mt Fujiyama in Japan, Mt. Stromboli in Mediterranean Sea.
   2. Dormant Volcanoes: When a volcano has not erupted for a long time but may suddenly become active, it is called a dormant volcano. ex. Mt. Vesuvius in Italy, Mt. Katmai in Alaska, and Barren Island in India.
   3. Extinct Volcano: Those volcanoes which have not erupted in the past since long and are not likely to erupt in the future are called extinct volcanoes. ex. Mt. Kilimanjaro in Tanzania.